Finally, in [1]}, the author proves the universality of QAOA using a line graph quantum architecture, which is not easily comparable to the method of showing ma-QAOA universality in this paper. The author mentions that this architecture is limited but says that the techniques used to prove QAOA universality can be expanded to higher dimensions. It would be of interest to determine if there are cases where the QAOA universality methods in [1]} require fewer operations to implement an arbitrary circuit than the method in this paper, and vice-versa. Additionally, fully-connected architecture and gates that act on \(n\)  qubits for all \(n \ge 2\)  are required in this implementation, whereas the line architecture in [1]} is much more sparse. It would be of interest to determine if there is a more natural method of using QAOA or ma-QAOA for computation on lattices such as the square grid or hexagonal lattice, which more closely model current quantum architecture [4]}, [5]}.
